Senior Full-Stack Product Engineer

Senior full-stack product engineer. Growth, billing, and experimentation across healthcare, fintech, and SaaS for 10+ years.

Selected work
Get in touch
Abdulsamii Ajala working on a laptop in a lounge
Signup conversion lift at Parsley Health
125%
Retention and shipment lift at Heroshe
~45%
Years shipping products end to end
10+
Countries on one Meta NPE team
5

Selected work

Products that moved the numbers, not just the pixels.

  1. 01Doubling signup conversion for a modern healthcare brandParsley Health · Senior Frontend Engineer125%
    Parsley Health join flow, the clinician-matching step
  2. 02Shipping growth experiments on Meta’s New Product Experimentation teamMeta · Senior Full-Stack Engineer, NPE5
    Abdulsamii with the NPE team holding a Meta box
  3. 03Rebuilding an ecommerce logistics frontend from WordPress to NuxtHeroshe · Lead Frontend Engineer~45%
    Led three developers through a TDD rebuild that lifted retention and shipment conversion ~45%.Heroshe
  4. 04A mentorship platform across web, mobile, messaging, and analyticsInneract Project · Full-Stack EngineerWeb + iOS + Android
    Uplift by Inneract Project, a social career network for designers
  5. 05Fintech SaaS for cooperative societies: loans, savings, and ledgersKoprative · Founder-engineer, full stackLoans · Savings · Ledgers
    A full-stack platform that moved cooperative institutions off spreadsheets.Koprative
  6. 06Hourfolk: a calmer way to work across time zonesHourfolk · Creator · design and engineeringOn the Chrome Web Store
    Hourfolk showing the local time and saved clocks for London, New York, and Tokyo

About

Hello, I’m Abdulsamii.

I’m Abdulsamii, a product engineer based in Nigeria. For ten years I’ve built for teams spread across time zones, from early-stage startups to Meta’s New Product Experimentation group, and I’ve learned that the best features are the ones you can measure.

My work sits where product, growth, and engineering meet: onboarding funnels, A/B experiments, analytics instrumentation, and the billing flows that turn usage into revenue. I own features end to end, from the first hypothesis to the dashboard that proves it worked. The same habit produced Hourfolk, a Chrome extension I built for anyone whose team or family lives in another time zone.

Away from client work I’ve trained and mentored hundreds of developers through the Andela Learning Community, CodeVillage, and community programs, and I still screen senior engineers for Andela.

Nigeria · working remotely across time zones

Abdulsamii on a call at a café counter
Abdulsamii seated in a wood-panelled lounge

Off-screen

  • Abdulsamii standing in an open-plan office
    Lanyard on. Shipping mode.
  • Abdulsamii speaking on stage with a microphone at DevFest
    DevFest Ilorin 2022. Home crowd, big stage.
  • Abdulsamii teaching a room of developers at their laptops
    A room full of first commits. Best energy there is.
  • Abdulsamii with teammates holding a Meta box
    Five countries, one squad. Meta NPE.
  • Abdulsamii at a desk by a sunlit window with a laptop
    Golden hour doubles as deep-work hour.
  • Abdulsamii at a marble café table checking his phone
    Coffee first. Then commits.
  • Abdulsamii in front of the Google Developer Groups DevFest banner
    Google Developer Groups, Ilorin. Giving back where it started.
  • Abdulsamii seated with folded arms beside a sign about writing code to solve problems at scale
    Solving problems at scale. Still the mission.
  • Abdulsamii smiling outdoors under a blue sky beside a thatched hut
    Out of office. Village air, zero notifications.
  • Abdulsamii sitting cross-legged on a rock in a river
    Stillness is a feature. Recharging by the river.
  • Abdulsamii in white walking across the courtyard in Madinah
    Madinah. Gratitude between sprints.
  • Abdulsamii smiling on a rope canopy walk among trees
    Canopy walk. No laptop, no regrets.
  • Abdulsamii grinning on a boat with waves behind him
    Boat day. Sea breeze beats screen glare.

Experience

Ten years, many time zones.

  1. 2024 – PresentFull-Stack Engineer · Inneract ProjectOwn end-to-end features on the Uplift platform, its analytics tool, and its React Native app.
  2. Mar – May 2025AI Trainer, Full-Stack · Mercor IntelligenceCreated and reviewed code-based prompts, solutions, and reasoning chains; annotated UX flows for model training.
  3. Sep 2022 – Mar 2023Senior Full-Stack Engineer, NPE · MetaPrototyped community products and validated growth hypotheses with controlled A/B experiments.
  4. 2021 – 2022Senior Frontend Engineer · Parsley HealthContributed to the join-flow redesign that lifted signup conversion 125%.
  5. 2021 – 2022React Native & Node.js Developer · StartHubBuilt Pass Tickets and the Hayak tourism app, including checkout, payments, and backend APIs.
  6. 2019 – PresentFull-Stack Developer · Arc.dev (Codementor)Deliver web and mobile applications for clients across industries, from architecture to deployment.
  7. 2019 – PresentTechnical Screener · AndelaEvaluate senior full-stack and mobile candidates on React, React Native, Node.js, and system design.
+ Earlier roles
  • 2018 – 2019Technical Team Lead · Fluidangle, Sacramento / RemoteLed 8 engineers; owned CI/CD and environments.
  • 2019 – 2020Lead Learning Facilitator · CodeVillage, IlorinDesigned the full-stack and algorithms curriculum.
  • 2017 – 2018Software Engineer · Swipemax, LagosDashboard APIs for financial transactions serving major banks.
  • 2017Software Engineer · Codesquad, IlorinAgile TDD client work; managed 15 engineers.
  • 2016 – 2017Frontend Engineer · Packer Labs, USADrinkTime dashboard on Firebase and GCP.
  • 2014 – 2016Frontend Engineer · Polesmusic · Cinsol, NigeriaFirst product roles.

Work with me

Three ways to start.

I take on a small number of engagements at a time, always with a measurable goal attached.

Start a project
  1. 01

    Growth engineering sprints

    Find the leak in your funnel and fix it with evidence. Instrumentation, experiments, and the UX changes they justify.

    • Onboarding and signup funnel redesign
    • A/B experimentation and controlled rollouts
    • Event tracking and analytics dashboards
  2. 02

    Billing and payments

    Checkout, subscriptions, and payment flows that convert and reconcile. Stripe, Paystack, PayPal, and local rails.

    • Subscription and checkout flows
    • Stripe, Paystack, PayPal, Monnify
    • Ledgers, invoicing, and dunning
  3. 03

    Full-stack product builds

    Web and mobile products owned end to end, from architecture to app-store submission.

    • Next.js and Node.js platforms
    • React Native apps for iOS and Android
    • Firebase, PostgreSQL, MongoDB, AWS

Writing & community

Notes from the work.

Open source

Community

  • Mentor and volunteer, Andela Learning Community (2019 – 2020)
  • Lead facilitator, SEEC Web Division, Ilorin (2016)
  • Trained and mentored hundreds of developers through ALC, CodeVillage, and community programs

Contact

Let’s build something that grows.

[email protected]
Hire me
Work with me