Senior Database Engineer

Were Capital on Tap
Capital on Tap started because small businesses were underserved. Big banks were slow their products werent fit for purpose and small business owners often couldnt access what they needed. We set out to fix that.

Today were a financial platform - not just a credit card company. We offer a best-in-class business credit card SME-focused spend management platform a savings product that hit 1 billion in funds within its first year and a growing suite of tools and financial products that make running a small business easier.

1000 employees 20bn in annual card spend 200000 customers 17000 Trustpilot reviews averaging 4.7 stars and were profitable. Weve done a pretty good job so far but were just getting started!

This is a Hybrid role the AI team work from our Moorgate (London) Offices 2 days per week.

The Role

Our platform runs and SQL Server on Azure and it has grown well beyond what it was originally designed for. Were hiring our first dedicated Database Performance Engineer to own performance and scale: to make the fast paths fast keep them fast as volume grows and give every engineer here the tooling and judgement to write data access that holds up in production.

Youll join a small agile team of DBAs and site reliability engineers in a hands-on senior individual contributor role. You wont be working a ticket queue. Youll choose the work that moves the needle on latency cost and reliability and youll be trusted to call out what needs re-architecting.

What Youll Do

• Own query and index performance across our transactional SQL Server estate using execution plans Query Store wait statistics real production telemetry or other data driven measures.
• Investigate and implement horizontal scaling techniques such as multi-cluster architecture contained availability groups sharding etc to ensure Capital on Taps distributed software estate can continue to support a fast growing customer base and increasing service count.
• Find and remove the bottlenecks on our latency critical paths starting with card authorisation and ledger read/writes and hold them to an agreed p99 budget.
• Own high availability and disaster recovery. Availability groups failover backup and restore testing against real RTO and RPO targets and the runbooks that go with them.
• Build and enhance self serve tooling to enable development teams to identify query plan regressions along with self service diagnostic tools to allow teams to debug their own query performance.
• Automate what is currently manual using PowerShell Python or Terraform and treat database configuration as code.
• Manage SQL Server cost as a first-class metric alongside latency and uptime.
• Work alongside Product Engineering and our data analytics team reviewing designs before they ship and levelling up how the whole engineering org thinks about data access.
• Evangelise advanced database technologies to the software engineering teams. Research demo and promote technologies such as graph databases and zero-downtime data migrations and how they can be used in EF via C#.

What Were Looking For

• Experience working with ORMs (ideally Entity Framework) and the particular performance tradeoffs that come with an ORM.
• Substantial experience running Microsoft SQL Server in production at scale whether that be self managed Managed Instances or on Azure SQL in a business where downtime and latency have direct commercial impact.
• Real depth in the internals. The query optimiser and plan cache indexing and statistics locking blocking and isolation levels tempdb and the wait types that tell you which of those is actually hurting you.
• A track record of specific measurable performance wins you can walk us through end to end.
• Experience scaling relational data past the point where tuning alone works. Partitioning archival denormalisation caching read replicas or a considered move to a different store.
• Comfortable writing application code not just scripts. T-SQL to an expert level plus PowerShell or Python and infrastructure as code.
• Hands-on with HA/DR design and with leading production incidents.
• Working knowledge of other database engines such as PostgreSQL and views on the relative pros/cons.
• An ability to translate technical concepts and tradeoffs to non-database specialists.

Diversity & Inclusion
We welcome consider and encourage applications from anyone who shares our commitment to inclusivity. Join us in creating a space where authenticity thrives and everyone can do their best work.

Great Work Deserves Great Perks
We try not to take ourselves too seriously (all the time) so we make sure our office is decked out with a pool table arcade machine beer tap and a couple of office dogs thrown in for good measure. Check out our benefits:
Private Healthcare including dental and opticians services through Vitality
Worldwide travel insurance through Vitality
Anniversary Rewards (-week fully paid sabbatical)
Salary Sacrifice Pension Scheme up to 7% match
Octopus EV Salary Sacrifice Scheme
28 days holiday (plus bank holidays)
Annual Learning and Wellbeing Budget
Enhanced Parental Leave
Cycle to Work Scheme
Season Ticket Loan
6 free therapy sessions per year
Dog Friendly Offices
Free drinks and snacks in our offices

Check out more of our benefits values and mission here.

Other Info
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Excited to work here Apply!
If youd like to progress your career within our fast growing profitable fintech then click apply and we will aim to get back to you within 3 working days (during busy periods this could take up to 5 working days.)