Documented engagement model
AI Agencies and Consultancies on Retainer in Europe (September 2026)
Agencies that document retainer engagements on their own sites or in published case studies, ranked by portfolio quality and credibility.
Each listed agency documents retainer engagements on its own site or in a published case study; the model is never inferred from a service list.
Top picks
- 1. Faculty — London · 3 documented clients
- 2. Pexon Consulting — Munich · €130-175/hr · 4 documented clients
- 3. Siili Solutions — Helsinki · €45-85/hr · 5 documented clients
Documented clients include
LähiTapiola Finance · Gebäudeversicherung Bern · Deutz · Henkel · Ambu · Banc Sabadell
Ranked agencies for retainer engagements
Rankings updated · Newest review
Top 30 of 56 agencies with documented retainer work.
Faculty
#1London, United Kingdom
Client evidence: 3 documented clients overall
Best for: Enterprises and public bodies that need AI deployed under regulatory or safety scrutiny.
Munich, Germany
Client evidence: 4 documented clients overall
Best for: Regulated German industrial and mid-market firms that want the model running inside their own Azure or AWS tenant.
Helsinki, Finland
Client evidence: 5 documented clients overall
Best for: Regulated Finnish and Nordic enterprises that need an AI system governed, certified and operated, not just delivered.
Madrid, Spain
Client evidence: 4 documented clients overall
Best for: Enterprises already committed to Azure that want an AI system delivered by a team with Microsoft-stack depth and named references.
Dublin, Ireland
Client evidence: 4 documented clients overall
Best for: Software vendors and public bodies modernizing an Azure platform, where new AI has to fit systems already carrying live volume.
Squirro
#6Zurich, Switzerland
Client evidence: 4 documented clients overall
Best for: Regulated enterprises buying a retrieval and knowledge platform with the delivery work attached, not a bespoke build.
Dublin, Ireland
Client evidence: 20 documented clients overall
Best for: Irish and European SMEs and founders buying a whole product build, with AI as one layer inside it rather than the whole engagement.
London, United Kingdom
Client evidence: 4 documented clients overall
Best for: Health and industrial companies taking a risk-scoring or compliance-reporting workflow from paper to a regulated digital platform.
Dmlab
#9Budapest, Hungary
Client evidence: 2 documented clients overall
Best for: Hungarian operators in energy, logistics or media that need a forecasting system wired into how the business already trades.
Limebit
#10Berlin, Germany
Client evidence: 2 documented clients overall
Best for: Pharmaceutical companies and statutory health insurers that need analysis to survive a regulatory review and the code to come with it.
Flobotics
#11Warsaw, Poland
Client evidence: 3 documented clients overall
Best for: Operations teams that want automation bought against a payback number, especially in healthcare revenue cycle.
Version 1
#12Dublin, Ireland
Client evidence: 6 documented clients overall
Best for: Insurers, brokers and public bodies automating document-heavy back-office work with an ISO 42001-certified delivery partner.
Hiflylabs
#13Budapest, Hungary
Client evidence: 8 documented clients overall
Best for: Banks, energy and manufacturing groups pairing an LLM or forecasting build with the data-platform work underneath it.
Xomnia
#14Amsterdam, Netherlands
Client evidence: 3 documented clients overall
Best for: Dutch enterprises whose model problem turns out to be a data-platform problem.
Neurons Lab
#15London, United Kingdom
Client evidence: 2 documented clients overall
Best for: Financial institutions that need agentic AI shipped inside regulatory constraints—training through production.
Amsterdam, Netherlands
Client evidence: 2 documented clients overall
Best for: Regulated institutions and retailers with a pricing, risk or monitoring problem that can be measured.
OstraconAI
Verified: the agency confirmed ownership from a company email address, and the listing passed editorial review#17Helsinki, Finland
Client evidence: 11 documented clients overall
Best for: Nordic marketing and sales teams that want AI tools built into HubSpot, Teams or Microsoft 365 and their own staff trained to run them.
Dublin, Ireland
Client evidence: 2 documented clients overall
Best for: Teams that want the senior consultant doing the build, with the architecture and its limits written down before delivery.
HolistiCRM
#19Budapest, Hungary
Client evidence: 7 documented clients overall
Best for: Banks, retailers and utilities that want a propensity or next-best-offer model on their own data, scored on a business rate.
Sngular
#20Madrid, Spain
Client evidence: 3 documented clients overall
Best for: Enterprises staffing a multi-year engineering program in infrastructure, banking or back-office automation with a single partner.
Adnovum
#21Zurich, Switzerland
Client evidence: 5 documented clients overall
Best for: Swiss institutions wanting a conversational AI system built into their own cloud and then operated for them.
Boldare
#22Amsterdam, Netherlands
Client evidence: 3 documented clients overall
Best for: Consumer-facing businesses adding an OpenAI-backed chatbot or generated content to a web platform Boldare builds or runs.
Found
#23London, United Kingdom
Client evidence: 8 documented clients overall
Best for: UK consumer brands in retail, insurance and hospitality that want AI applied inside paid search, SEO and campaign data.
Madrid, Spain
Client evidence: 11 documented clients overall
Best for: Consumer-facing brands and large operators in Spain evolving a digital product over years, with AI added into an existing workflow.
Budapest, Hungary
Client evidence: 3 documented clients overall
Best for: Industrial and pharmaceutical groups that want their own engineers taught to run AI projects before they buy a system.
Berlin, Germany
Client evidence: 7 documented clients overall
Best for: Product owners adding AI to an app that already has users, rather than starting from a model.
Contiamo
#27Berlin, Germany
Client evidence: 4 documented clients overall
Best for: German municipal utilities, housing companies and consumer brands adding GPT-based assistants to customer service and content work.
Ekimetrics
#28London, United Kingdom
Client evidence: 4 documented clients overall
Best for: Consumer and industrial brands that need marketing spend measured and modeled rather than an AI system built.
Dublin, Ireland
Client evidence: 2 documented clients overall
Best for: Enterprises standardizing on ServiceNow that want customer workflows implemented and the platform's AI features actually adopted.
Bismart
#30Barcelona, Spain
Client evidence: 6 documented clients overall
Best for: Organizations whose AI plans depend on fixing the data layer first, especially in healthcare, public services and tourism.
About this list
A retainer buys continuity: the agency that built the system keeps operating, tuning and extending it for a monthly fee, instead of handing it over at the end of a project. In AI work that continuity is worth more than in most software, because models drift, prompts age, source data changes shape and the regulatory ground under a deployed system moves. Every agency on this page documents a retainer or managed-service relationship on its own site or in a published case study. The chip is never inferred from a pricing page or a service list.
The documented relationships show what the model buys. Siili Solutions maintains Bobotin, the retrieval-augmented agent that drafts customer-service replies at LähiTapiola Finance, as an ongoing managed service under GDPR and EU AI Act constraints rather than as a delivered build. Adnovum operates the Berna claims voicebot it architected for Gebäudeversicherung Bern, a system that handles up to 2,700 calls a day during storm events. OstraconAI's outreach engagement for Gosta Labs is described as an ongoing retainer, with prompts tuned weekly. Bismart's work for Banc Sabadell and Segittur is documented as ongoing evolution and maintenance, and Inbold has been Ambu's single production partner for instructions-for-use since 2016. Pexon Consulting's private AI platform at Deutz reached more than 5,000 users, the kind of footprint that needs an operator, not a handover.
Read a retainer proposal with three questions. What is the operating scope: monitoring, retraining, prompt and data maintenance, or new features on the same budget? What does the agency measure, and does it publish it? And what happens at exit: who owns the pipelines, the evaluation sets and the documentation when the retainer ends? An agency that can answer the third question in writing is selling continuity; one that cannot is selling dependency. Scores rank portfolio quality and credibility; placement is never sold.
Intro by Gabor Kiss, curator · How we rank
Expert Insight
Why the engagement model matters
Deployed AI degrades without an operator: models drift, prompts age and source data changes shape, so the question is not whether someone maintains the system but who, at what price and against which metrics.
A documented retainer is evidence the agency has run a system past launch, which a portfolio of delivered builds cannot show.
Continuity and dependency look identical in month one; the exit terms, ownership of pipelines and evaluation sets, and published operating metrics tell them apart.
Frequently asked questions
A documented ongoing relationship in which the agency operates, maintains or keeps extending a system for a recurring fee: a managed service, a monthly retainer, a multi-year production partnership. The agency describes the model on its own site or a published case study documents it, with the source URL stored per client. A pricing page offering retainers is not evidence; a named client on one is.
Retainers are priced as a monthly block derived from the hourly bands each agency publishes, scaled to the operating scope. Published rates for the agencies here run across the European range on our rate index; the block a retainer buys depends on whether it covers monitoring alone or monitoring plus retraining, prompt maintenance and new features. Ask for the scope in writing before comparing monthly figures.
A retainer keeps the work on the agency's side of the fence: the agency operates and extends a system it usually built. Team extension puts named engineers inside your team, working your backlog under your leadership. Retainers suit a deployed system that needs an operator and a stream of bounded improvements; extension suits continuous product work with no natural end. The team-extension page lists the agencies that document that model.
Who owns the code, pipelines, evaluation sets and documentation; what the handover period is; and whether the agency's platform components are licensed or transferred. Some agencies on this page build on their own platforms, which is legitimate but changes what an exit looks like, so ask in month one, not month twelve.