Senior Software Engineer · Barcelona, Spain
Mustafa Onal.
Software, from idea to production.
I build SaaS platforms, applied AI systems, and developer tools. Hands-on across backend, frontend, architecture, and cloud infrastructure. Currently at Workfully and building Kortyx.
Get in touchAbout me
I'm a senior software engineer based in Barcelona, working across SaaS platforms, applied AI, and developer tooling. I take products from ambiguous requirements through architecture, implementation, and production.
At Workfully, I build recruitment software and contribute to agentic automation, connecting backend business rules, operational workflows, and reliable marketplace signals.
Previously at CleverConnect, I led the architecture and most of the hands-on engineering for a new AI interviewing product, from multilingual voice conversations to durable background analysis and enterprise beta delivery.
I also build Kortyx, a TypeScript framework for explicit agent workflows. It reflects how I like to engineer: clear contracts, observable behavior, and tools that make complex systems easier to understand.
My background spans recruitment, energy, insurance, and financial services. I work closely with product and leadership teams, mentor engineers, and stay hands-on with the systems we ship.
Selected engineering work
Kortyx
Active beta · Personal project
A TypeScript framework for AI agents with explicit workflows, streaming, persistent state, and human-in-the-loop interrupts. I build the runtime, provider integrations, React bindings, CLI, and self-hosted Studio. The framework is Apache-2.0; the Studio UI is source-available.
Workfully Marketplace Operations
Production · Workfully
Recruitment software that helps delivery teams identify stalled hiring pipelines and act on them. My work spans backend business rules, the Operations Control Center, and reliable metrics that support revenue forecasting and agentic marketplace automation.
Qualify AI Interviewing
Enterprise beta delivered · CleverConnect
Led the technical foundations of a multi-tenant AI interviewing product with multilingual voice and chat, a conversational recruiter interface, and durable interview analysis. Built production observability, prompt-version tracking, and deterministic citation checks.
Sub-second voice response · About $0.50 per 20-minute interview in model and speech costs
Soleilex CRM & Business Automation
Delivered · Soleilex
A custom platform connecting customer records, construction quotations, contract signatures, and invoicing. Integrated Qonto payment verification and the French Cadastre API, with invoices generated directly from approved quotations.
Bespoke quote preparation: about 4 hours to 10 minutes
NextShopKit SDK
Past project · Not actively maintained
A published TypeScript SDK for custom Shopify storefronts with Next.js. Built typed Storefront API abstractions, metafield parsing, cart state management, and automated npm releases.
Where I have worked
Workfully
CleverConnect
Soleilex
Société Générale
LSEG
Senior AI Engineer
Workfully
Jun 2026 - Present
Barcelona, Spain
Build recruitment platform capabilities and contribute to agentic automation, aligning backend behavior with marketplace business rules.
Created the Operations Control Center to surface stalled hiring pipelines, explain delivery issues, and support operational decisions at scale.
Delivered the initial AWS/Kestra infrastructure, CI automation, historical capture, and core metrics in two weeks.
Established shared business definitions and reliable data foundations for revenue forecasting, invoicing, and agent workflows.
Relevant skills
Full Stack Engineer · Applied AI
CleverConnect
Jul 2025 - Jun 2026
Paris, France · Remote
Led architecture and the majority of hands-on engineering for a greenfield, multi-tenant AI interviewing product, taking it to enterprise beta usage.
Built multilingual voice and chat workflows with LiveKit and LangGraph, plus durable interview analysis with Temporal and self-service analysis reruns.
Established a TypeScript monorepo with shared contracts, testing, GitLab CI, and Kubernetes/Argo CD delivery.
Connected Langfuse traces to prompt versions, production costs, and user feedback; implemented deterministic citation validation.
Mentored three engineers, supported their transition from Angular to React, and enforced architectural boundaries with custom ESLint rules.
Relevant skills
Full Stack Developer
Soleilex
Feb 2021 - Apr 2025
Paris, France · Remote
Built interconnected CRM, content, and commerce products using React, Next.js, Node.js, PostgreSQL, Shopify, and Strapi.
Automated quotations, contract signatures, and invoicing, reducing bespoke construction quote preparation from about four hours to 10 minutes.
Integrated Qonto payment verification and the French Cadastre API into operational workflows.
Delivered a headless Shopify storefront with configurable solar kits and a CMS that non-technical teams could manage independently.
Relevant skills
Frontend Developer & Product Owner
Société Générale Assurances
Sep 2019 - Nov 2020
Paris, France
Developed a React and Strapi internal product used by more than 200 people across nine countries.
Combined frontend delivery and Product Owner responsibilities, coordinating user research, data models, and Agile delivery across UX, engineering, and compliance.
Prototyped and adapted the experience to different market needs using Figma and Adobe XD.
Relevant skills
Internship
London Stock Exchange Group (LSEG)
Mar 2019 - Aug 2019
Paris, France
Collaborated with developers to translate design specifications into implementation-ready assets.
Contributed to interface design and website improvements using Adobe XD, with a focus on consistency and web standards.
Relevant skills
Where I have studied
Paris Dauphine
IAE Gustave Eiffel
Marmara University
Master of International Business Management and New Communication Technologies
Université Paris Dauphine - PSL
2019 - 2020
Paris Area, France
Related courses include Project Management, Digital Transformation, Information Technologies.
A master program with strong focus on new digital technologies and implementations.
Full English track courses in an international environment.
Key learning topics
Master of Business Administration - MBA
IAE Gustave Eiffel
2018 - 2019
Paris Area, France
Related courses include Corporate Finance, International Negotiation and Leadership.
Participated in negotiation simulations and real business case scenarios.
Full English track courses in an international environment.
Key learning topics
Bachelor of Business Administration - BBA, Decision Sciences
Marmara University
2014 - 2018
Istanbul, Turkey
Obtained business-related skills on Finance, Accounting, Statistics, Human Resources, Business Law.
Improved mathematical methods for managerial decisions with my major degree Decision Sciences.
The BBA program of Marmara University places its graduates to top companies in Turkey.
Full English track courses.
Key learning topics