Freelancer profile translated to English.
Back to original languageAbout Guillaume
Guillaume Agis – Fullstack Developer | Android & Backend Golang Expert
Since 2010, I have proactively supported companies, SMEs, and startups in the design, evolution, and modernization of their mobile and backend solutions. My role goes beyond development: I advise, guide technical choices, anticipate risks, and propose robust, scalable architectures tailored to business objectives.
Specializing in Android Kotlin / Jetpack Compose and Golang backend, I work on environments requiring performance, reliability, and scalability: microservices, gRPC, AWS, PostgreSQL, advanced APIs, and distributed systems.
Key Figures
+45 projects delivered (€2,000 to €50,000 packages)
15 years of experience in mobile & backend development
Loyal clients since 2010 ⭐⭐⭐⭐⭐
References: Rolland Garros, Heetch, Cheerz, Airbus, MYM,
Backend
Golang, microservices, gRPC, REST
Scalable architecture, high availability, performance optimization
NestJS, Typescript, NodeJS
Cloud deployment: AWS (ECS, Lambda, API Gateway, S3, CloudWatch)
PostgreSQL: optimization, indexing, complex queries
Advanced API integration: OpenAI, ChatGPT, AI tools
Android Mobile
React Native, Kotlin Android, Jetpack Compose, MVVM, Clean Architecture
Development of stable, robust, and performant applications
UX optimizations, network and memory performance
Complex integrations: services, offline processing APIs
Superwall, RevenueCat.
My Approach
I help companies make the best technical decisions upstream, by clarifying their needs, proposing an optimized architecture, and ensuring lasting support after delivery.
I am committed to providing performant, scalable, and maintainable solutions, while remaining available and responsive.
English
Native or bilingual
French
Native or bilingual
Can work on-site
Paris (up to 20km), Paris (up to 50km), Lyon (up to 50km), Marseille (up to 50km), Bordeaux (up to 50km)
Experience
- MYMTechnical LeadHEALTH AND WELLNESSJuly 2025 - Today (11 months)Tech Lead at MYM, responsible for a team of 5 developers in an agile environment. Supervision and maintenance of over 10 microservices in Golang, used by millions of users each month. In charge of the development and reliability of our APIs, the integration platform for our partners. Implementation of an automated documentation generation system from microservices, ensuring consistency and speed of updates. Technical guidance, code reviews, and continuous optimization of the ecosystem's performance and scalability.
- 2060.LifeCore Team MemberJanuary 2025 - July 2025 (6 months)Foundation (non-profit) with the goal of slowing down aging by 2060.In my free time, I manage the technical aspects of the foundation's various initiatives (investment club, website, etc.).
- AdnalyzeCTO / Full Stack Dev / Team LeadDIGITAL AND ITJune 2017 - Today (9 years)Toulouse, FranceSupports over 40 small and large companies in developing and scaling their applications, software systems, and IoT.Major clients include: Colgate, EDF, Cheerz, AXA, Airbus Defence and Space.- Managed a team of 12 remote developers.- Managed clients primarily in the UK, Israel, and France.- Developed Android applications, IoT projects (Glasswear, beacons, etc.), and backends.Key Technologies: Android, Kotlin, MVVM, Koin, Room, unit tests, Espresso, RxAndroid, AWS, Firebase.
Reviews
Allan
KAIYO MEDIA
Reviewed on 12/19/2024
This new mission with Guillaume went very well.
Guillaume takes the time to explain things well, he is responsive to feedback, and deadlines are met.
He positions himself as a CTO by proposing several solutions aligned with the project's objectives.
Allan
KAIYO MEDIA
Reviewed on 10/25/2024
Guillaume brilliantly designed an MVP perfectly aligned with the quote's expectations.
Thanks to his expertise, he also provided valuable support in project management, ensuring each step was carried out smoothly and coherently.
He clearly explained the challenges encountered and the solutions implemented to optimize the application as much as possible.
The result is a fluid, intuitive, easy-to-use MVP that even exceeds my expectations.
I give him my full trust for the future, without any hesitation.
Recommendations
FP
AS
+4
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Education
- Master of computer science in software engineeringEpitech2014
- Bachelor - Business Information TechnologyHelsinki2012