Senior Ruby Engineer

About the company

At Tembo, we’re on a mission to make home happen — helping people buy their first home, remortgage, or move up the ladder, and helping thousands more save smarter towards home ownership.

We’re tackling one of the biggest challenges of our generation : helping people get on and move up the property ladder. Through innovative mortgage products, smart affordability schemes, and savings tools like our Lifetime ISA and Home Saver, we help families who’ve been locked out of home ownership finally get the keys to their own place. Every day, our work directly changes lives — enabling people to buy their first home, reduce their costs, or build a brighter financial future.

That sense of real-world impact is what drives everything we do, and why people love working here.

Now, we’re looking for a talented Senior Ruby Engineer to join the team and help build out our financial infrastructure for the years to come.

We’re a mission centric organization that holds our values close :

• Find a way - representing our desire to innovate and also leave no stone unturned to help find a customer a way to get on the ladder
• It's all about the people - customers, colleagues, partners - we’re all human and without them we are nothing
• If you don’t like it change it - as a startup we’re constantly listening to every source of data and evolving, every opinion counts

We are rated 4.9
* on Trustpilot with every single customer review celebrated :

https : / /  / review /

We are well funded by Goodwater Capital, Aviva, McPike Family Global Office, Ascension, Love Ventures as well as a suite of ethical backers such as Fair by Design, Barrow Cadbury, Joseph Rowntree Foundation and Big Society Capital.

You can read more about us and our mission on our website : https : / /  / our-mission

Tembo is on the lookout for a passionate Senior Ruby Engineer to join the savings team. We recently launched a Cash ISA proposition to the market, powered by our proprietary savings technology and things have taken off in a big way. We have seen explosive growth and we are looking to bolster the team. You'll be working to launch new savings products to our growing number of customers, support continued scale and build tools to allow operations teams to self serve on all of their needs.

• Service Creation :
  Design and develop resilient, scalable backend services in Ruby that power critical real-money systems, ensuring reliability and consistency in high-stakes environments.
• Feature Development :
  Lead and contribute to the full lifecycle of product features—from ideation to deployment and maintenance with a strong emphasis on data accuracy, security, and transactional integrity.
• Maintenance and Optimization :
  Continuously monitor and improve system performance, scalability, and reliability. Take ownership of system uptime and proactively mitigate bottlenecks or failures in cash reconciliation flows.
• Bug Identification and Resolution :
  Diagnose and resolve complex production issues in high-volume transactional environments. Implement effective monitoring and alerting to catch anomalies before they impact users.
• Code Reviews and Best Practices :
  Champion clean, maintainable, and well-tested Ruby code. Conduct detailed code reviews, mentor junior engineers, and foster a strong engineering culture built on quality and accountability.
• Cross-Functional Collaboration :
  Partner with product managers, QA, and design teams to align on priorities, define clear acceptance criteria, and deliver consistent value to the business with each release.
• Technical Investigations :
  Lead technical deep-dives and spike solutions to evaluate technologies, libraries, and approaches for improving system reliability, auditing, and financial reconciliation accuracy.
• Open Standards :
  Support our commitment to observability and open standards. Contribute to initiatives around Open Telemetry, OpenAPI, and other tools that improve transparency and traceability across services.

• At least 5 years of professional experience in software development, with a strong focus on Ruby on Rails
• Must have experience with payment processing systems and real…