Experience

Work timeline

Tubonibo Williams (Isaac): roles across startups and product teams, backend leadership, fullstack delivery, and mobile.

Play Empire
Backend Developer & LeadNOV / 25 to PRESENT
Leading backend engineering on a sweepstakes platform, owning core APIs, service architecture, and delivery standards for a product that must stay reliable under high engagement. Work spans auth and account flows, transactional integrity, admin and player-facing services, and mentoring the backend track so features ship cleanly without compromising compliance-sensitive game and wallet logic.
Play Empire
Backend Developer & LeadNOV / 25 to PRESENT
Leading backend engineering on a sweepstakes platform, owning core APIs, service architecture, and delivery standards for a product that must stay reliable under high engagement. Work spans auth and account flows, transactional integrity, admin and player-facing services, and mentoring the backend track so features ship cleanly without compromising compliance-sensitive game and wallet logic.
Sportsbook Engine
Fullstack Web & Mobile DeveloperAUG / 25 to NOV / 25
Fullstack DeveloperAPR / 24 to NOV / 24
Backend DeveloperAUG / 23 to APR / 24
Operated in a versatile, multi-hat role, frequently taking ownership of end-to-end mobile and web application development. This spanned building iOS and Android applications with React Native, developing responsive web versions, and diving into backend systems as needed to implement features, fix issues, and ensure cohesive system performance.
Sportsbook Engine
Fullstack Web & Mobile DeveloperAUG / 25 to NOV / 25
Fullstack DeveloperAPR / 24 to NOV / 24
Backend DeveloperAUG / 23 to APR / 24
Operated in a versatile, multi-hat role, frequently taking ownership of end-to-end mobile and web application development. This spanned building iOS and Android applications with React Native, developing responsive web versions, and diving into backend systems as needed to implement features, fix issues, and ensure cohesive system performance.
Hex Software
Fullstack DeveloperJAN / 26 to PRESENT
Fullstack DeveloperSept / 24 to JAN / 25
After establishing the technical foundation in 2024, my role has evolved to include direct client engagement and end-to-end project ownership. From December onward, I've served as a forward-facing engineer, working closely with stakeholders to rapidly understand requirements, translate ideas into precise technical solutions, and ensure high client satisfaction through fast, reliable delivery and clear communication.
Hex Software
Fullstack DeveloperJAN / 26 to PRESENT
Fullstack DeveloperSept / 24 to JAN / 25
After establishing the technical foundation in 2024, my role has evolved to include direct client engagement and end-to-end project ownership. From December onward, I've served as a forward-facing engineer, working closely with stakeholders to rapidly understand requirements, translate ideas into precise technical solutions, and ensure high client satisfaction through fast, reliable delivery and clear communication.
Profibook
Fullstack DeveloperAUG / 24 to AUG / 26
Joined as a core engineer in a demanding startup setting, where I turned high-level, loosely-defined ideas into production-ready applications, often building with imagination under tight deadlines. Spearheaded the full-stack creation of a SaaS platform using React/Next.js, NestJS, and .NET Core, delivering responsive UIs, real-time chat/notifications, and optimized microservices that boosted API performance by 35%. Embraced a 'ship fast, refine faster' mentality, pushing through ambiguity to deliver functional, stable features and keep the product moving forward.
Profibook
Fullstack DeveloperAUG / 24 to AUG / 26
Joined as a core engineer in a demanding startup setting, where I turned high-level, loosely-defined ideas into production-ready applications, often building with imagination under tight deadlines. Spearheaded the full-stack creation of a SaaS platform using React/Next.js, NestJS, and .NET Core, delivering responsive UIs, real-time chat/notifications, and optimized microservices that boosted API performance by 35%. Embraced a 'ship fast, refine faster' mentality, pushing through ambiguity to deliver functional, stable features and keep the product moving forward.
Ftimer
Implementation Specialist (Part-Time Contract)AUG / 25 to DEC / 25
Brought in on a part-time, expert capacity to accelerate a critical implementation that required specialized experience. I worked alongside the in-house development team to architect and execute the solution, enabling them to achieve their objectives more effectively and deliver a robust, production-ready feature ahead of schedule.
Ftimer
Implementation Specialist (Part-Time Contract)AUG / 25 to DEC / 25
Brought in on a part-time, expert capacity to accelerate a critical implementation that required specialized experience. I worked alongside the in-house development team to architect and execute the solution, enabling them to achieve their objectives more effectively and deliver a robust, production-ready feature ahead of schedule.
Zeavak
React Native DeveloperJUN / 24 to PRESENT
Build and maintain high-performance, scalable, and responsive mobile applications using React Native. Write clean, maintainable, and well-documented code, ensuring efficient performance and reliability of mobile apps. Collaborate with cross-functional teams including designers, product managers, and backend developers to create seamless and intuitive user experiences.
Zeavak
React Native DeveloperJUN / 24 to PRESENT
Build and maintain high-performance, scalable, and responsive mobile applications using React Native. Write clean, maintainable, and well-documented code, ensuring efficient performance and reliability of mobile apps. Collaborate with cross-functional teams including designers, product managers, and backend developers to create seamless and intuitive user experiences.
DocsGenie (formerly UsefulPDF)
Fullstack DeveloperFEB / 23 to AUG / 23
Acted as a delivery-focused developer in a fast-paced startup, responsible for shipping promotional, email, and functional UI interfaces rapidly and precisely. Balanced frontend speed with backend stability, optimizing server-client interactions to reduce API latency by 40% while implementing fault-tolerant systems that maintained 99.9% uptime, enabling smooth day-to-day operations.
DocsGenie (formerly UsefulPDF)
Fullstack DeveloperFEB / 23 to AUG / 23
Acted as a delivery-focused developer in a fast-paced startup, responsible for shipping promotional, email, and functional UI interfaces rapidly and precisely. Balanced frontend speed with backend stability, optimizing server-client interactions to reduce API latency by 40% while implementing fault-tolerant systems that maintained 99.9% uptime, enabling smooth day-to-day operations.
Mambadev
Fullstack DeveloperNOV / 21 to JAN / 23
Gained foundational, high-impact experience across a diverse portfolio, from enterprise-grade SaaS and e-commerce systems to early-stage startup MVPs. This environment demanded versatile problem-solving and ownership: I developed and optimized critical backend APIs with NestJS and PostgreSQL, improved query performance by 35%, reduced system downtime by 30%, and contributed to CI/CD pipelines. The role honed my ability to deliver secure, maintainable software across varied business contexts under demanding conditions.
Mambadev
Fullstack DeveloperNOV / 21 to JAN / 23
Gained foundational, high-impact experience across a diverse portfolio, from enterprise-grade SaaS and e-commerce systems to early-stage startup MVPs. This environment demanded versatile problem-solving and ownership: I developed and optimized critical backend APIs with NestJS and PostgreSQL, improved query performance by 35%, reduced system downtime by 30%, and contributed to CI/CD pipelines. The role honed my ability to deliver secure, maintainable software across varied business contexts under demanding conditions.

Work timeline

Play Empire

Sportsbook Engine

Hex Software

Profibook

Ftimer

Zeavak

DocsGenie (formerly UsefulPDF)

Mambadev