About Antithesis:

Antithesis helps engineering teams find and fix bugs that traditional testing methods miss.

Our platform runs entire systems in a deterministic simulation, breaks them in every imaginable way, and provides engineers with root cause analysis and perfect reproduction. The result is faster debugging, more reliable software, and more confidence in what ships.

As AI accelerates software development, the need for reliable verification is only increasing. Antithesis exists to solve that problem.

We are well-funded, deeply technical, and building a category-defining platform for modern software reliability.

About the Role:

As a Senior Account Manager, you will own a portfolio of Antithesis customers across EMEA, with responsibility for the relationship from post-sale handoff through renewal and expansion. You will become a trusted partner to customers ranging from engineering teams and technical leaders to CTOs and CEOs, helping them realize value from Antithesis while identifying opportunities to broaden our partnership.

This is a quota-carrying role with direct ownership of renewal and expansion revenue. You’ll work closely with New Logo Account Executives, Forward Deployed Engineers, Customer Success Managers, Support Engineers, Product, and Engineering to understand customer needs, manage account health, and turn strong customer relationships into durable revenue growth.

This is a Founding Account Management role based onsite at our London Headquarters. You’ll have significant autonomy, shaping how account management operates in this region as Antithesis scales. We’re looking for someone who is growth-minded, highly curious, comfortable with technical SaaS products, and energized by working with enterprise customers in an early-stage environment.

What You’ll Do:

• Own a portfolio of EMEA customers from post-sale handoff through renewal and expansion, building trusted relationships with technical and executive stakeholders and positioning Antithesis as a strategic, increasingly valuable partner.

• Own renewal and expansion revenue, developing account strategies that drive strong retention, identify growth opportunities, and expand Antithesis into additional teams, use cases, and business units.

• Lead the commercial lifecycle for your accounts, including renewal planning, forecasting, pricing, negotiations, and expansion opportunities, with a focus on predictable revenue outcomes and no avoidable surprises.

• Understand customer goals, usage, and account health to proactively identify risk, strengthen adoption, and address potential churn well before renewal. Bring the right internal teams together to resolve challenges and protect the customer relationship.

• Maintain strong operational discipline across your book of business, using internal sales and account management systems to maintain accurate customer data, track account lifecycle and health, manage forecasts, and generate reporting on at-risk and growth accounts.

• Partner cross-functionally and help build the EMEA account management motion, working with Sales, Customer Experience, Product, and Engineering to surface customer insights, improve the customer experience, and establish scalable processes and best practices for account management at Antithesis.

Qualifications We’re Looking For:

• 5+ years of experience in quota-carrying Account Management or a similar post-sale commercial role.

• Proven track record of owning renewal and expansion revenue and consistently meeting or exceeding retention and growth targets.

• Experience managing a defined book of enterprise B2B clients made up of technical and executive stakeholders, including Engineering leaders, CTOs, and other senior decision-makers.

• Strong full lifecycle sales skills with experience leading renewals, expansions, pricing, negotiations, and contract discussions.

• Operational rigor, including maintaining accurate customer and opportunity data in various CRM/sales tools supporting forecasting, identifying account risk, expansion opportunities, and revenue trends.

• Experience working cross-functionally with New Logo Sales Executives, Support Engineers, Forward Deployed Engineers, Customer Success Managers, Product, and Engineering teams.

• Ability to operate independently in a fast-moving, early-stage environment and help build processes and playbooks as the organization scales.

• Experience working with EMEA customers and buying environments; with the willingness to work from the London office.

Nice to Have Skills:

• Experience managing customers for developer tools, infrastructure, cybersecurity, cloud, testing, observability, or other highly technical products is strongly preferred.

• Experience selling to engineering organizations and engaging stakeholders such as Engineering Managers, VPs of Engineering, CTOs, and technical executives is particularly valuable.

• Experience managing complex enterprise accounts, multi-year agreements, usage-based or platform SaaS models, and expansion across multiple teams or business units is also highly relevant.