Senior Proposal Writer

Senior Proposal Writer- Open to UK, France and Netherlands

The Senior Proposal Writer leads the most complex, high-stakes and non-standard RFX responses from intake to submission, as a trusted partner to Sales. Alongside Solution Consulting and subject-matter experts, this role guides strategy shaping, pulls the contributions together and delivers proposals that are clear, accurate and give buyers confidence in the outcomes OneStream delivers. The role also coaches other writers and helps raise the standards, content and tools the whole team works with.

Primary Duties and Responsibilities

• Lead complex, high-stakes and non-standard RFI, RFP and RFQ responses from intake to submission, maintaining the highest standards of execution and submission integrity.

• Work with Sales to understand the deal behind each response (the buyer’s priorities, the competition, the evidence that builds confidence) and shape the proposal around it.

• Coordinate concurrent contributions from Sales, Solution Consulting, Finance, Legal, Product and other specialist teams.

• Set and run the project cadence (including kick-off, RFP tool setup, check-ins, reviews, packaging and close-down), creating clarity, facilitating multiple contributors and consistently meeting deadlines and milestones.

• Take each response over the line, checking structure, formatting, accuracy and clarity before it goes.

Knowledge & Continuous Improvement

• Keep knowledge of OneStream’s platform and competitive positioning current, and catch outdated or inaccurate product information before it goes out.

• Spot gaps and help close them, in how responses are crafted and positioned and in the standards, workflows, templates, tools and content library behind them.

• Turn lessons from completed proposals and their outcomes into guidance, content and examples the whole team can use.

• Use AI tools thoughtfully across the workflow, and share the prompts and practices that improve insight, quality, consistency and pace.

Collaboration, Coaching & Influence

• Build strong relationships with the teams relied on, know their remit and boundaries, and route requests well so that colleagues’ time is used efficiently.

• Coach junior and mid-level writers with practical feedback on their work and the thinking behind strong proposal decisions, and help new joiners get up to speed.

• Shape how the team approaches content, quality and process, and model the standards expected of the team.

Competencies

• Sound judgement on structure, messaging and emphasis when requirements are ambiguous, incomplete or non-standard, a willingness to adapt when the standard approach doesn’t fit, and ownership of the decisions made.

• Influence without direct authority, built on trust.

• The confidence to hold a reasoned position with Sales on quality and standards, with an open mind and a realistic view of what each deal needs.

• A commercial view of how proposals drive revenue, and the focus to put effort where it most influences the buyer’s decision.

• Self-motivation and accountability, working independently and delivering as part of a team.

• A habit of learning, spotting opportunities in their own skills and developing them.

Required Education and Experience

• Bachelor’s degree in Business Administration, Communications, English, Marketing or a related field, or equivalent professional experience.

• Seven or more years writing and managing RFI, RFP and RFQ responses, working alongside sales teams on competitive, high-value deals.

• Professional experience using AI tools in a writing, editing or content workflow.

• Experience coaching or mentoring colleagues and contributing to team knowledge sharing.

Preferred Education and Experience

• Experience in a cloud or SaaS environment, ideally in finance or a related domain.

• Experience with Ombud or a comparable proposal management platform.

• Experience with Salesforce or a comparable CRM in opportunity and proposal workflows.

• APMP preferred but not required.

Knowledge, Skills, and Abilities

• Ability to analyse complex business processes, enterprise technology and buyer requirements, and work out what they mean for the response and where the gaps are.

• Exceptional writing, editing and verbal communication, turning complex technical, business and commercial information into accurate, persuasive content.

• Ability to prioritise competing projects, manage time effectively and stay accurate as deadlines shift.

• Solid grasp of sales frameworks, buyer enablement, and revenue operations.

Supervisory Responsibilities

n/a.

Travel

Regular travel is not expected for this position.