Prompt Engineer

AI Image Generation Specialist — Mindy Support Application

This portfolio demonstrates end-to-end prompt engineering workflow: writing prompts, generating image batches, reviewing every output against defined quality criteria, selecting the best result, and documenting issues with actionable feedback.

Case Studies

309

Images Reviewed

Criteria Per Image

Winners Selected

Case Study — No Winner Selected

Luxury Vacation Editorial — All 80 Images Rejected

Sometimes no output meets quality standards. This case study demonstrates the ability to reject an entire batch when systematic issues prevent any image from meeting the brief — and to document actionable feedback for the next iteration.

Prompt

Relaxed luxury vacation scene, woman lying on a white sunbed with long legs raised, overlooking an infinity pool merging with the turquoise ocean, clear blue sky, summer atmosphere, tanned skin glowing under sunlight, elegant jewelry on wrists and ankle, cinematic composition, photorealism, ultra HD, vibrant colors, editorial lifestyle aesthetic

--ar 9:16--v 7

10 shown below — representing all 20 batches (80 images total)All 80 rejected

Batch 1Reject

Legs flat, not raised. Jewelry is oversized chunky gold cuffs — more costume armor than elegant. Feet have fused toe areas. Sunbed sitting in water rather than beside pool.

Batch 2Reject

Major anatomy failure. Hand has fused/boneless fingers. Feet enormous relative to forearm — scale mismatch. Legs flat, not raised. Pool doesn't merge with ocean convincingly.

Batch 3Reject

Legs flat, not raised. Hand has only 3-4 distinguishable fingers. Wrist bracelets melted into skin. Feet heavily blurred with fused toes. No ankle jewelry visible.

Batch 4Reject

Closest to prompt — pool/ocean merge works. But feet are blurred smudges used to hide anatomy issues. Composition is a wrist jewelry close-up, not editorial body shot. No ankle jewelry.

Batch 5Reject

Only a single arm visible. No legs, no feet, no raised-leg pose at all. Looks like a jewelry product shot, not a lifestyle scene. Arm terminates abruptly at elbow.

Batch 6Reject

Legs bent sideways/crossed, not raised. Fingers partially fused together. Jewelry on one wrist only, not on both wrists and ankle. Casual lounging, not editorial composition.

Batch 7Reject

Knees raised tent-like — not the elegant extended pose implied. Left foot toes fused together. Jewelry barely visible. Awkward composition with knees dominating frame.

Batch 8Reject

Legs flat, not raised. Toes irregular — pinky toe area merged. Jewelry on one ankle only, none on wrists. Pool/ocean merge is good but the missing raised-leg pose is a deal-breaker.

Batch 9Reject

Legs in impossible pretzel configuration — crossed in a way that defies joint articulation. High-heeled sandal contradicts relaxed sunbathing. Fingers fused and malformed where hands cross.

Batch 10Reject

Best composition of the set — pool/ocean merge works. But legs flat, not raised. Right foot small toes blur together. Jewelry only on one wrist. Close but still fails core pose requirement.

Verdict

No image selected — full re-generation required

Systematic Issues Found Across All 80 Images

1. "Legs raised" consistently ignored. Not a single image across 20 batches shows the elevated leg pose requested. The model defaults to flat or bent legs on a lounger. 2. Foot/toe anatomy fails in every image. Fused toes, missing small toes, unnaturally smooth arches, or deliberately blurred feet to hide defects. 3. Hand/finger issues in 60% of images. Fused fingers, missing digits, boneless/waxy appearance. Many images strategically crop hands to avoid rendering them. 4. Jewelry placement never matches prompt. Prompt asks for jewelry on "wrists and ankle" (plural). Most show only one wrist bracelet. Ankle jewelry almost never appears. 5. Aggressive cropping hides problems. Many outputs show only fragments rather than the full editorial lifestyle composition requested. 6. Over-saturation undermines photorealism. Hyper-saturated colors and painterly skin tones contradict the "photorealism" requirement.

Recommended Next Steps

Prompt restructuring: • Move "legs raised high" to beginning of prompt for higher weight • Add explicit: "feet elevated above hip level, legs extended skyward" • Add negative prompts: --no flat legs, bent knees, cropped body, close-up • Reduce quality modifiers that bias toward painterly rendering Parameter changes: • Use --style raw for more literal prompt interpretation • Try --iref with a reference photo showing the exact legs-raised pose • Lower --stylize to reduce artistic interpretation of the pose • Consider --ar 16:9 landscape format to better accommodate the full scene Post-generation: • Use inpainting to fix toe/finger anatomy on closest candidates • Consider compositing: take the best pool/ocean background and the best figure separately

Case Study 1

Photorealistic Equestrian Editorial

A complex photorealistic prompt tested across 3 batches (12 images). Each image reviewed for composition, face detail, text accuracy, anatomy, lighting, and prompt adherence.

Prompt

photorealistic portrait of a young woman with mixed Asian-Caucasian features, mid-20s, light brown hair in two long braids, serious expression gazing upwards, wearing a black crop top with "MUSTANG" text, silver choker necklace, large ornate belt buckle, frayed plaid mini-skirt in gray tones, black leather thigh-high boots, arm bracelets, sitting bareback on a majestic white horse with flowing mane, low-angle shot from below emphasizing power and height, bright blue sky with scattered white clouds, sunny outdoor lighting with soft shadows, high detail on skin texture, fabric folds, horse fur, cinematic composition, ultra-realistic

--ar 9:16--v 7--stylize 200

Batch A — 993b89cc4 outputs

A-0Issues

Good low-angle composition and cloud background. "MUSTANG" text distorted but partially readable. Strong belt buckle detail. Boots visible at bottom edge.

A-1Issues

Best expression of the batch, natural upward gaze. Text partially obscured by pose. Minor hand/rein clarity issue. Excellent skin texture and choker detail.

A-2Issues

Dramatic angle with good sky. Hair rendered with bangs instead of braids — deviates from prompt. Text warped and hard to read.

A-3Pass

Best composition with dramatic backlighting creating cinematic rim light. Strong confident pose. Text partially distorted but acceptable. Finalist.

Batch B — a6643ab54 outputs

B-0Issues

Decent face detail and flowing horse mane. "MUSTANG" partially readable. Slight anatomy oddness at hip/skirt area. Solid but not standout.

B-1Pass

Most natural expression across all 12 images. "MUSTANG" is clearest here. Clean anatomy. Slightly less dramatic angle. Finalist.

B-2★ Selected

Most photorealistic face in the entire set. Great earring and jewelry detail. "MUSTANG" fairly readable. Strong natural skin texture. Best balance overall.

B-3Issues

Good gaze and chunky chain necklace. "MUSTANG" partially visible. Skirt plaid pattern less defined. Solid but not finalist material.

Batch C — 4a2c91714 outputs

C-0Issues

Good full-body composition. "MUSTANG" misspelled as "MUSTNG" — clear text generation failure. Otherwise strong image.

C-1Reject

Dramatic low angle but "MUSTANG" text completely illegible. A key prompt element cannot be read at all, making this unsuitable.

C-2Issues

Most naturalistic face with beautiful skin texture. Angle less dramatic than requested and shirt text barely visible. Would be winner if text weren't critical.

C-3Reject

Text illegible and hand/finger articulation unclear. Two significant issues make this unsuitable for selection.

Selection Result

Winner: B-2

Image B-2 ★ Selected

Selected as the best output from 12 candidates across 3 batches. This image achieves the strongest balance across all criteria — combining the most photorealistic face with acceptable text legibility and strong composition.

While A-3 had better backlighting and B-1 had clearer text, B-2 delivers the most convincing photorealism, which is the primary quality goal for this editorial brief.

Low-angle composition with sense of power and height
Most photorealistic face across all 12 outputs
"MUSTANG" text readable (partially distorted — acceptable)
Natural anatomy with no articulation errors
Earrings, choker, belt buckle, braids all visible
White horse with flowing mane clearly in frame
Dramatic blue sky with cinematic cloud composition
High detail on skin texture, fabric, and horse fur

Case Study 2

Dynamic Fruit Explosion — iPhone Wallpaper

A product-style wallpaper prompt tested across 9 batches (36 images). Representative outputs shown with quality assessment.

Prompt

iPhone wallpaper style, 4K ultra-detailed: Fresh watermelon slices burst apart in mid-air, sending crimson juice spraying outward in dynamic arcs. The fruit fragments tumble and spin through the frame while droplets scatter in all directions. Seeds fly loose from the exploding flesh as the vibrant liquid creates sweeping trails of summer color.

--ar 9:16--v 7

Representative outputs — 1 per batch9 of 36 images

Batch 1Pass

Excellent composition with slices stacked dynamically. Rich magenta/crimson palette. Seeds and juice droplets clearly visible. Strong wallpaper candidate.

Batch 2Issues

Good splash dynamics but composition slightly off-center. Vibrant purple/magenta tones. Some juice arcs feel artificial.

Batch 3Pass

Beautiful dynamic juice arc. Multiple fragments tumbling naturally. Excellent crimson and green contrast. Seeds scattered realistically.

Batch 4Issues

One large slice dominates instead of "burst apart" effect. Less dynamic than prompt requests. Colors are strong.

Batch 5★ Selected

Best wallpaper candidate. Strong splash dynamics with multiple slices at different angles. Excellent droplet scatter pattern. Vibrant crimson-magenta palette with nice depth of field. Most realistic liquid dynamics.

Batch 6Issues

Good burst composition with dark-to-crimson gradient. However, liquid dynamics feel artificial — juice arcs look rendered rather than photorealistic. Seeds visible but overall lacks the natural splash feel of Batch 5.

Batch 7Issues

Composition slightly cluttered with too many elements competing. Background blur good but framing could be tighter.

Batch 8Issues

Gorgeous color but slices feel static rather than "bursting apart." More still-life than the dynamic explosion prompt describes.

Batch 9Pass

Dynamic and vibrant with good motion sense. Includes strawberry-like elements not in prompt. Otherwise strong wallpaper output.

Selection Result

Winner: Batch 5

Batch 5 — 8d9774d9 ★ Selected

Selected as the best wallpaper from 36 candidates across 9 batches. This image achieves the most realistic liquid dynamics — the juice spray and droplet scatter feel genuinely photographic rather than rendered.

Multiple watermelon slices at different angles create the "burst apart" energy the prompt describes. The vibrant crimson-magenta palette with natural depth of field makes it ideal as an iPhone wallpaper.

Watermelon slices clearly bursting apart in mid-air
Crimson juice spraying outward in dynamic arcs
Seeds visibly flying loose from the flesh
Vibrant summer color palette (crimson, green, magenta)
Centered composition suitable for phone wallpaper
4K-quality detail on fruit texture and liquid dynamics
Dark gradient edges allow UI readability as wallpaper

Case Study 3

Kawaii Mech Fashion Editorial

A complex multi-element prompt combining character design, fashion, and mech robotics. 10 batches (39 images). Representative outputs shown with assessment of prompt adherence.

Prompt

A young Asian woman with platinum white hair styled in high twin pigtails, sharp facial features, subtle makeup, serious expression, standing confidently in a full-body pose. She wears an oversized puffy bomber jacket in pastel pink and light blue with robotic arm details, a white hoodie underneath with a small logo, layered gold necklaces, a small pink crossbody bag, white high-waisted shorts, white crew socks, and chunky platform sneakers in pink with blue accents. Behind her looms a massive robotic teddy bear mech suit in matching pastel pink and blue, with a cute oversized bear head, mechanical joints, and armored limbs, blending kawaii and futuristic elements. Soft pink studio background, high-fashion editorial style, vibrant pastel color palette, detailed textures on fabrics and robotics, cinematic lighting

--ar 9:16--v 7

Representative outputs — 1 per batch10 of 39 images

Batch 1Pass

Strong composition with model centered and mech framing from behind. All wardrobe elements present and accurate. Bear mech head cropped at top; background too saturated/magenta vs requested soft pink.

Batch 2Pass

Excellent full-body composition with mech bear clearly visible. Nearly all wardrobe elements faithfully rendered. Mech could be larger/more imposing; shorts read more as hoodie-dress silhouette.

Batch 3Pass

Bear mech prominently displayed with cute head, mechanical joints, matching pastels. Outfit, expression, hair closely match prompt. Cinematic lighting and pink gradient well executed. Strong finalist.

Batch 4Reject

Strong pose and outfit elements present. However, mech lacks recognizable bear head — reads as generic pink robot, missing a core prompt element. Pigtails rendered as small buns instead of high twin pigtails.

Batch 5Pass

Good full-body editorial shot with recognizable bear mech featuring blue accents. All wardrobe elements align well. Mech positioned beside rather than "looming behind" — weakens dramatic scale contrast.

Batch 6Pass

Strong editorial quality with excellent cinematic lighting and clearly visible bear mech head with glowing pink accents. Great bomber jacket texture. Minor hand distortion (common AI artifact).

Batch 7Issues

Good mood and color palette, great bomber jacket texture. Bear mech head barely visible/cropped, reading as generic robot. Shorts not visible — hoodie appears as dress. Pose feels stiff.

Batch 8Pass

Very strong prompt adherence — bear mech clearly rendered with cute head, joints, and pastel armoring. All outfit elements and accessories well-represented. Balanced composition with soft pink gradient.

Batch 9Issues

Most vibrant pastel palette of all batches. However, mech skews purple/magenta rather than pastel pink/blue — shifts from kawaii toward cyberpunk aesthetic. Shorts appear as bodysuit.

Batch 10★ Selected

Best overall execution. Clean composition with good model/mech separation. Recognizable bear head, all outfit elements present. Uses --sref style reference for cross-batch consistency. Most polished editorial feel.

Selection Result

Winner: Batch 10

Batch 10 — 8168ad00 ★ Selected

Selected as the best output from 39 candidates across 10 batches. This image was generated using --sref style reference to maintain cross-batch consistency, demonstrating advanced parameter usage. The result is the most polished editorial composition in the set.

Clean separation between model and mech allows both elements to read clearly. The bear head is recognizable, all outfit elements are present, and the overall framing achieves the high-fashion editorial look the prompt targets.

Platinum white hair in high twin pigtails — accurate
Pastel pink/blue bomber jacket with robotic details
White hoodie, gold necklaces, crossbody bag visible
Robotic teddy bear mech with recognizable bear head
Clean model/mech separation for visual clarity
--sref style reference used for cross-batch consistency
Soft pink studio background with cinematic lighting
Most polished high-fashion editorial feel

Case Study 4

Hyper-Realistic Beach Close-Up — Sand Heart

A highly detailed photorealistic prompt with challenging anatomy (feet/toes) and a specific compositional element (sand heart on skin). 36 batches (142 images) — the largest generation run in this portfolio. Demonstrates systematic review of a high-volume batch with recurring failure modes.

Prompt

A mesmerizing hyper-realistic close-up digital artwork masterpiece capturing a person's tanned legs relaxed on a sunlit beach, feet buried in soft white sand with toes peeking out, one knee bent with a heart shape meticulously formed from piled sand grains on the skin, subtle shadows and highlights emphasizing the smooth skin texture and sand details, blurred background suggesting vast sandy shore and distant ocean waves under a bright sky, intricate details on individual sand particles with varying sizes and clumping, skin pores with natural oil sheen and subtle hairs, dynamic composition emphasizing relaxation, love, and playful creativity in a serene beach vibe, ultra-detailed 8K resolution, cinematic depth of field with sharp focus on the heart and knees while softly blurring the feet and background, vibrant color palette blending tans, whites, golds, and soft blues seamlessly

--ar 9:16--v 7--stylize 200

Representative outputs — 10 of 36 batches142 total images

Batch 1★ Selected

Strongest execution. Sand heart clearly outlined on knee skin. Natural leg anatomy and correct toe count. Convincing pores and oil sheen. Depth of field sharp on heart, ocean blurred. Reads as real photo.

Batch 2Issues

Heart drawn on sand beside the leg rather than formed on the skin as prompt specifies. Composition misses the core requirement. Skin texture decent but sand has overly glittery artificial look.

Batch 3Reject

Complete prompt failure. Generated a fantasy face portrait with iridescent crystal effects. No legs, no feet, no sand heart, no beach scene. Model latched onto "hyper-realistic close-up" and ignored all compositional instructions.

Batch 4Pass

Sand heart clearly visible on upper knee. Natural leg positioning with correct toe count. Warm skin sheen, ocean softly blurred. Slightly over-sparkly sand texture but overall very strong.

Batch 5Reject

Same failure as Batch 3 — face/shoulder glamour portrait with iridescent glitter instead of legs-on-beach scene. Recurring model failure mode: defaults to portrait despite specific body-part instructions.

Batch 6Pass

Sand heart clearly formed on knee. Natural pose, realistic skin sheen and texture. Background ocean blur attractive. Sand slightly excessive glitter quality but composition matches prompt well.

Batch 7Reject

Face/shoulder portrait with glitter. No legs, feet, or sand-on-skin heart present. Third instance of the recurring portrait failure mode across this generation run.

Batch 8Issues

Shows legs and sand heart, but heart formed near foot on sand surface rather than on skin. Toes appear blobby and merged — toe count ambiguous. Close to prompt but anatomy holds it back.

Batch 9Reject

Heart sculpted on sand surface, not on skin as prompt specifies ("heart shape meticulously formed from piled sand grains on the skin"). Prompt requires heart directly on knee/thigh — this places it on the ground against the shin. Misses the core creative element.

Batch 10Reject

Fantasy glitter portrait with upper body visible. Heart shape in glitter on thigh area but dominant composition is glamour shot with heavy iridescent effects. Not a photorealistic beach scene.

Key Finding: Recurring Failure Mode

40% of batches generated wrong composition

ML Team Feedback

Across 36 batches, approximately 40% generated face/shoulder glamour portraits with fantasy glitter effects instead of the requested legs-on-beach composition. The model appears to have a strong bias toward face-centric compositions when encountering "hyper-realistic close-up" combined with "skin texture" descriptors, overriding explicit instructions about body part framing (legs, feet, knees). Recommended mitigations: • Add explicit negative prompt: --no face, portrait, shoulders, upper body • Move "legs" and "feet" to the beginning of the prompt for higher weight • Reduce ambiguous quality modifiers ("masterpiece", "mesmerizing") that may bias toward portrait compositions • Use --style raw to reduce artistic interpretation • Consider image reference (--iref) with an example leg composition to anchor the framing

Selection Result

Winner: Batch 1

Batch 1 — 0de15020 ★ Selected

Selected as the best from 142 candidates across 36 batches. This image correctly interprets every compositional element: sand heart on skin, legs relaxed, feet with toes in sand, blurred ocean background.

The skin texture achieves genuine photorealism with visible pores and natural oil sheen. Critically, the foot anatomy is correct (five toes, natural proportions) — a common failure point in AI-generated images. The cinematic depth of field keeps the heart in sharp focus while softly blurring the background.

Sand heart clearly formed on skin (knee/thigh)
Natural leg positioning with one knee bent
Correct foot/toe anatomy (5 toes, natural proportions)
Hyper-realistic skin texture with pores and oil sheen
Cinematic depth of field — heart sharp, background blurred
Warm tan/gold/blue color palette as specified
Ocean waves and bright sky visible in blurred background
Reads as genuine photograph, not AI-generated

Skills & Tools

What I Bring to the Role

Midjourney v5–v7

Prompt writing, parameters, profiles, --cref, --sref

Prompt Engineering

Structured prompt design, iteration, optimization

Visual Quality Assessment

Lighting, color, composition, anatomy, style

Batch Generation & Review

Systematic evaluation across large image sets

Selection Criteria Design

Defining repeatable rules for consistent decisions

Python & JavaScript

API automation, batch processing, scripting

Documentation

Guidelines, processes, decisions — reusable by teams

English B2+

Client communication and written documentation

Available for this role

Remote — 14:00–22:00 or 16:00–24:00 Kyiv time

pyavchik@gmail.com LinkedIn Profile