Localization Portfolio · 2025–2026

Diego Sánchez Casillas

LQA Specialist · ES-ES & LATAM Spanish  |  Legal Translator EN–ES  |  AI/LLM Language Evaluator

✉diegosanchezcasillass@gmail.com 🔗linkedin.com/in/diego-sánchez-casillas 📍Morelia, Mexico · Remote
🎮
Credited in the official staff roll of Let It Die: Inferno (GungHo Online, 2025) for Spanish LQA — a distinction typically reserved for core team members, not contractors. Project completed on-site in Tokyo, Japan with Kinsha Co., Ltd.

About this Portfolio

Overview

What I do

Linguistic Quality Assurance for games (EN→ES-ES, JP→ES-ES), AI/LLM output evaluation in Spanish (LATAM & ES-ES), and legal translation (EN→ES). I work across the full localization pipeline — from string review and bug reporting to regression testing and gold master sign-off.

My differentiator

One of very few LATAM-native specialists with hands-on ES-ES (European Spanish) game localization experience. This dual-variant fluency is rare and in high demand across the European market, particularly for titles targeting both Spain and Latin America simultaneously.

Languages

Spanish LATAM — Native Spanish ES-ES — Professional English — C1 Advanced (CAE) Japanese — JLPT N4

Tools & Skills

Phrase (TMS/CAT) Jira LQA Bug Reporting Regression Testing UI/UX Testing String Review Style Guide Application LLM Annotation

What's in this portfolio

All samples are original work created for portfolio purposes. Real project materials from Kinsha Co., Ltd. are covered under NDA. Each sample is designed to reflect real-world LQA and evaluation scenarios encountered in professional game localization and AI/LLM projects.

UI String LQA (EN→ES-ES) LQA Bug Report Dialogue Localization (EN→ES-ES) LLM Output Evaluation (EN→ES)

UI String Localization

EN → ES-ES · Character-constrained
Action RPG — HUD & Menu Strings
Character-limited UI strings for an action RPG. Constraints simulate real platform requirements (console HUD, button prompts, inventory menus). European Spanish (ES-ES) target.
ES-ES UI/HUD Char-constrained
String ID EN Source ES-ES Translation Limit Notes
HUD_001 Press [A] to interact Pulsa [A] para interactuar ✓ 26/30 «Pulsa» preferred over «Presiona» in ES-ES register.
HUD_002 Hold [B] to sprint Mantén [B] para correr ✓ 22/25 «Correr» chosen over «esprintar» — natural ES-ES, avoids anglicism.
INV_003 Equip Equipar ✓ 7/10 Standard term — consistent with style guide.
INV_004 Unequip Desequipar ✓ 10/12 Preferred over «retirar» for terminological consistency with INV_003.
INV_005 Item cannot be discarded No puedes desechar este objeto ⚠ 30/28 — TRIMMED Original translation 32 chars. Rewritten to fit limit without omitting meaning.
MENU_006 Save & Quit Guardar y salir ✓ 15/18 Standard — matches ES-ES platform conventions.
MENU_007 Continue without saving? ¿Continuar sin guardar? ✓ 22/30 Opening «¿» included — mandatory punctuation in ES-ES. Often missed by LATAM translators.
MENU_008 New Game+ Nueva partida+ ✓ 14/16 «Partida» over «juego» — more natural in gaming context for ES-ES.
NOTIF_009 Achievement unlocked! ¡Logro desbloqueado! ✓ 20/24 Opening «¡» included. «Logro» is the standard ES-ES term (vs. «trofeo» on PlayStation).
NOTIF_010 Connection lost. Reconnecting… Conexión perdida. Reconectando… ✓ 31/35 Ellipsis retained as a single character (…) per ES-ES typography convention.

LQA Bug Reports

Linguistic defect documentation
Bug Report #LQA-0047 — Register Error / Tone Inconsistency
Action RPG · ES-ES · Tutorial sequence
ES-ES Major
LQA-0047
Major
Register / Tone
ES-ES
Tutorial — Stage 1
Open
String ID
TUT_ES_0112
Issue
Character uses «tú» form throughout the game (informal address). In this string, the translation switches to «usted» (formal address), breaking consistency and the established character voice.

Current (incorrect): "Señor, usted debe presionar el botón para continuar."
Expected
Suggested fix: "Pulsa el botón para continuar."

Removes erroneous formal address. Aligns with «tú» register used in all other tutorial strings. Also replaces «presionar» with «pulsar», consistent with ES-ES button prompt conventions established in HUD strings.
Steps to Reproduce
1. Launch game → New Game
2. Complete intro cinematic
3. Enter Tutorial Stage 1
4. Trigger first prompt — string TUT_ES_0112 appears in dialogue box
Bug Report #LQA-0061 — Missing Punctuation / Typography
Action RPG · ES-ES · Inventory screen
ES-ES Minor
LQA-0061
Minor
Typography
ES-ES
Inventory → Confirm dialog
Open
String ID
INV_CONFIRM_ES_004
Issue
Interrogative sentence missing opening inverted question mark (¿), which is mandatory in Spanish orthography per RAE guidelines. This is a recurring error pattern — LATAM translators frequently omit this mark as it is not used in LATAM informal digital writing.

Current (incorrect): "Seguro que quieres desechar este objeto?"
Expected
Suggested fix: "¿Seguro que quieres desechar este objeto?"

Add «¿» at the start of the string. ES-ES style guide and RAE standard both require opening punctuation. Recommend a global search for all interrogative strings missing «¿» to identify similar instances.
Steps to Reproduce
1. Open Inventory
2. Select any item → press Discard
3. Confirmation dialog appears — string INV_CONFIRM_ES_004 visible

Dialogue Localization

EN → ES-ES · Character voice & tone
Ice Mage Tutorial — Fantasy RPG Dialogue
Tutorial dialogue for a composed, authoritative NPC character. Focus on maintaining character voice, natural ES-ES phrasing, and functional clarity for gameplay instructions.
ES-ES Dialogue Tutorial
EN Source ES-ES Translation Localization Notes
So, you're finally awake. Try moving with the left stick. Así que por fin despiertas. Intenta moverte con la palanca izquierda. Tone adapted for composed, mystical character. «Palanca» preferred over «joystick» — natural ES-ES.
Good. Now, focus your energy and press the button to cast an ice spell. Bien. Ahora canaliza tu energía y presiona el botón «A» para lanzar un hechizo de hielo. «Canaliza» chosen over «enfoca» — enhances magical register, fits character voice. Button label kept per platform style guide.
Don't rush. Precision matters more than speed. No te precipites. La precisión vale más que la velocidad. «Precipites» over «te apresures» — more refined tone appropriate for the NPC's authoritative voice.
Freeze your enemies before they can strike. Congela a tus enemigos antes de que puedan atacar. Natural phrasing. «A» personal pronoun included as required by ES-ES grammar for direct objects referring to people.
You've done well. The path ahead will demand more of you. Lo has hecho bien. El camino que te aguarda te exigirá más. «Te aguarda» chosen over «que hay por delante» — more literary register consistent with character. Maintains formal tone without using «usted».
Remember: magic has a cost. Use it wisely. Recuerda: la magia tiene un precio. Úsala con sabiduría. «Con sabiduría» preferred over «sabiamente» — sounds more deliberate and weighted, matching the NPC's wisdom-teacher archetype.

LLM Output Evaluation

EN → ES · Annotation & quality scoring
Evaluation Sample — Instruction-following & Fluency (ES-ES)
Evaluating a model's Spanish output for fluency, register accuracy, cultural appropriateness, and instruction-following. Annotated with structured feedback for retraining pipelines.
ES-ES LLM Eval Annotation
Prompt given to model Write a formal customer service response in European Spanish (ES-ES) to a user who reports that their game save file was corrupted. Apologize, explain next steps, and maintain a professional tone throughout.
Model Output (to be evaluated)
Hola! Lamentamos mucho que hayas tenido este problema con tu archivo de guardado. Esto puede pasar a veces y entendemos que es frustrante. Para solucionar esto, te recomendamos que intentes restaurar desde la nube si tienes activada la sincronización. Si no funciona, contacta a nuestro equipo de soporte y ellos te ayudarán. ¡Gracias por tu paciencia!
Fluency
7/10
Register
5/10
Accuracy
8/10
Cultural Fit
6/10
Instruction-following
6/10

Structured Annotation — Issues Identified

  • Register Opening «Hola!» is too informal for a formal customer service context in ES-ES. Expected: «Estimado/a usuario/a» or «Buenas tardes». Model defaults to LATAM-casual register despite explicit ES-ES formal instruction.
  • Register «Esto puede pasar a veces» is colloquial and dismissive — inappropriate register for acknowledging a customer's issue. Weakens the apology required by the prompt.
  • Fluency «Si no funciona, contacta a nuestro equipo» — omits the required «a» before «nuestro equipo» in some constructions; also abrupt transition. Flow is functional but not polished.
  • Accuracy Response covers the core content (apology, next steps) but does not clearly structure them as required. Steps are embedded in casual prose rather than explicitly enumerated.
  • Cultural Closing «¡Gracias por tu paciencia!» uses «tú» — inconsistent with the formal «usted» register expected in ES-ES formal customer service. In ES-ES B2C formal communications, «usted» is standard.
Reference Output (what an ideal response looks like)
Estimado/a usuario/a:

Lamentamos profundamente el inconveniente ocasionado por la corrupción de su archivo de guardado. Somos conscientes de lo frustrante que puede resultar esta situación y le pedimos disculpas por las molestias.

Para resolver su caso, le recomendamos seguir estos pasos:
1. Si tiene activada la sincronización en la nube, intente restaurar su partida desde el menú de opciones.
2. Si el problema persiste, póngase en contacto con nuestro equipo de soporte a través de [enlace/correo], indicando su nombre de usuario y la plataforma utilizada.

Nuestro equipo le atenderá en el menor tiempo posible. Agradecemos su paciencia y comprensión.

Un cordial saludo,
Equipo de Atención al Cliente