Timo J.-Senior Frontend Engineer & Tech Lead

Co-founded a software agency building custom web and cross-platform products. I owned the technical decisions across the whole portfolio and led 12 people, while carrying delivery planning, process and client relationships for 11 clients across 3 industries.

• Technical leadership: owned the technical decisions for the codebase across every project — stack, architecture, code conventions and the tooling the team worked with — and led the developers on how work got built through code reviews, pair programming and mentoring across a team ranging from junior to senior, keeping the codebase coherent as the portfolio and the team grew

• Delivery planning against the financial plan: built the company's financial plan and derived from it the billable hours each developer had to reach per month and the hours each project could absorb to stay within budget; planned capacity and scope against those figures and negotiated budgets and delivery dates directly with clients

• Client ownership: technical contact across the portfolio — requirements gathering and prioritisation, scoping and estimates, timeline communication, budget negotiation, and consistent transparency throughout delivery

• Team and people: owned the hiring and interview process end to end and took responsibility for offboarding where it was needed; designed an onboarding that got new developers productive within 1–2 days; cleared blockers daily and kept a close eye on where effort was creating value and where it was not

• Process ownership: consolidated a micro-service landscape spread over 15+ repositories into a single monorepo, cutting backend development time by ~40% and simplifying releases for 6 engineers; set up deployment pipelines with GitHub Actions and GitLab CI; ran retrospectives and turned the feedback into concrete changes; introduced AI agents into day-to-day development

• Delivered short-staffed: when the team shrank from 8 developers to 2, restructured scope, introduced AI-assisted development to hold the schedule and took on Go backend work alongside my own frontend scope

• Architecture and code: defined the architecture for every project in the portfolio — the structure the rest of the team built within — and wrote roughly 90% of the frontend code myself, from SSR applications with Next.js and Remix to cross-platform apps with Capacitor

• From zero to production: took a practice management platform — administration, inventory, integrated online shop, chat messenger — from an empty repository to production. Live in 7 markets with at least 7 more coming up, serving tens of thousands of users

• Delivery under pressure: built and shipped a replacement online shop for a Fortune 250 client in 4 days, restoring order intake while their global shops had been offline for several weeks

• Design system: built a cross-project design system used across 7 products, so new projects and features started from a shared, consistent base

• Cross-platform and real-time: built iOS and Android apps with Capacitor for a client live event with 1,000+ participants — web sockets and push notifications for real-time content, Stripe payments supporting PayPal, Apple Pay, Google Pay and cards

Key technologies: React, TypeScript, Next.js, Remix, GraphQL, ConnectRPC, Redux, Zustand, Go, Node.js, Turborepo, Nx, Capacitor, Ionic, WebSockets, Stripe, PostgreSQL, Playwright, Cypress, Vitest, Storybook, GitHub Actions, GitLab CI, Claude Code, Cursor, GitHub Copilot

Short-term engagement to bring a React/Unreal Engine product to release readiness for a conference the same month.

• Developed a React/TypeScript/Redux application integrated with an Unreal Engine app, and built the communication layer between the two
• Implemented and improved video sequences
• Fixed remaining bugs, built the final features and improved the overall look, feel and flow on both mobile and desktop clients

Key technologies: React, TypeScript, Redux, Unreal Engine, Responsive Design

Created platform components shared between 20+ product teams and reaching millions of users.

• Built customer-facing components and applications with React, TypeScript, GraphQL and Redux for 18+ million users
• Planned and implemented XING's central comment, like and share system
• Developed central components for XING's design system and planned the internal release processes for its component library across 20+ product teams
• Built a Microsoft Outlook add-in with React/Redux and worked across several customer-facing React applications in a micro-service environment
• Implemented automated testing processes including E2E tests with Cypress.js
• Collaborated with product management, UI/UX design, native developers and QA in a KANBAN setup, and shared learnings in company-wide presentations

Key technologies: React, TypeScript, JavaScript, GraphQL, Redux, Design Systems, Micro-frontends, Cypress.js, KANBAN, Git