The SaaS Software Stack Your Company Runs On, Not Sells
There are two stacks in a software company and people constantly conflate them. One is the infrastructure the product is built from. The other is the software the company itself runs on: where deals are tracked, where customers complain, where invoices are raised, where decisions are written down. The second stack gets bought carelessly, holds the most irreplaceable data, and is far harder to leave.
Don't pay full price to build this.All 105 SaaS tools below come with a discount code, a startup programme or free credits.Claim these perks →
Two stacks, and only one of them is portable
The product stack is engineering-owned, documented in code, and swappable with effort. Databases can be migrated, hosts can be changed, and the whole thing is version controlled. The company stack is different. It is bought by whoever felt the pain first, configured in a web interface, undocumented, and full of records that exist nowhere else.
That asymmetry should change how you buy. Nobody signs a three-year database contract without review, yet teams routinely commit their entire sales history to a CRM chosen in an afternoon because it had a good free tier. The deals, the email threads, the ticket history and the ledger are the company's memory, and the vendor holding them has enormous leverage at renewal.
So the ordering principle for this stack is exit cost first, features second, price third. Ask what leaving looks like before you ask what it does. If the answer is a CSV of the fields the vendor thinks are important, with attachments and activity timelines left behind, price the tool as though you will never leave, because you will not.
CRM: bought too early far more often than too late
Before roughly your twentieth customer, a CRM is overhead. A spreadsheet with company, contact, stage, next action and date does everything a two-person team needs and costs nothing to change. The signal to buy is not a revenue milestone, it is when two people need the same pipeline and you cannot tell who spoke to whom last week.
When you do buy, the split is between a full suite that also handles marketing email and support, and a focused sales tool that does pipeline well and integrates outward. Suites reduce plumbing and give one customer record. Focused tools are pleasanter to actually use daily, and sales teams that dislike the CRM simply do not update it, which makes the data worthless.
The discounting here is the deepest in the category, with programmes that cut a professional or enterprise tier by most of its price in the first year for qualifying early-stage companies. Take it with eyes open. A year of near-free enterprise CRM is excellent if that platform was your destination anyway, and expensive if it parks your commercial history somewhere you cannot afford at list price.
Support: a shared inbox until it visibly breaks
Start on a shared address on your own domain. Owning the address is the point, because it means the conversation history is yours and moving desks later is a migration rather than a loss. Founders answering support directly for the first few hundred conversations is not a stopgap, it is the cheapest product research available.
Buy a helpdesk when three things are true at once: more than one person answers, you cannot tell what is unresolved, and you are answering the same question repeatedly. The third is the one that justifies the spend, because a knowledge base and canned replies deflect volume in a way that no amount of inbox discipline does.
Choose between a ticketing desk and an in-app messaging tool by where your customers already are. Enterprise buyers email and expect SLAs and reporting. Self-serve users want a widget in the product and get frustrated by ticket numbers. Both categories run long, generous early-stage programmes, running from six months free to multi-year tapering discounts, precisely because switching later is so painful.
Marketing email and the deliverability tax
Keep transactional and marketing email on separate systems and separate sending domains. Password resets and receipts must arrive. Campaigns will occasionally get flagged. Sharing a domain between them means one bad send damages the deliverability of the emails your product depends on, and repairing a domain reputation takes weeks you cannot compress.
For marketing, the free tiers are unusually good and hold for a long time at small list sizes. What you pay for later is automation depth, segmentation and deliverability support. Judge on the billing metric before anything else, because contact-based pricing charges you for people who never open, and list hygiene becomes a direct cost saving rather than a nicety.
Set up authentication properly on day one: SPF, DKIM and DMARC on the sending domain, and a warm-up if you are moving an existing list. This is twenty minutes of DNS work that determines whether your email reaches inboxes at all. Teams skip it, see poor open rates, blame the platform, and switch vendors without fixing the actual cause.
Money, paperwork and the written record
Banking, accounting and document signing are the least exciting and the most consequential parts of this stack. A startup-focused bank that issues a virtual card per vendor turns subscription control from a spreadsheet exercise into a switch you can flip. Accounting software should be chosen by whichever system your accountant works in, because their time is billed to you.
The written record deserves the same care. A docs and wiki tool holds specifications, decisions, onboarding and meeting notes, and it becomes the thing new hires learn from. Judge it on search quality and export fidelity rather than on aesthetics. Nested pages that export as an unusable folder of orphaned markdown are a lock-in mechanism, whatever the marketing says.
Contracts and signatures round it out. You need something that produces a legally valid signed PDF with an audit trail and stores it where finance can find it. This is a commodity, several vendors run startup pricing, and it is one of the few places in the stack where picking on price is entirely rational.
Buy versus build, and getting your data back out
Almost nothing in the company stack is worth building. The exception is the small internal tool that reads from these systems and answers a question specific to your business, such as a dashboard joining product usage to deal stage. Build the join, buy the systems. Teams that invert this end up maintaining a worse CRM instead of shipping product.
Treat portability as an operational habit rather than a purchase-time question. Schedule a quarterly export from every system holding customer data, drop it somewhere you control, and confirm it opens. It costs an hour and it converts a vendor negotiation from a hostage situation into a commercial discussion, because you can credibly leave.
Getting the sequence right and claiming the programmes attached to each layer is what makes this stack affordable while it is being assembled. This directory's SaaS category covers CRM, support, email, banking, accounting and document tooling with their current founder terms and eligibility, so you can buy the layer you need now and know what it costs you the year after.
The offers mentioned above
Pulled live from the directory, so what you see here is what the listing says.
HubSpot
Marketing & Growth
$14,000
Percentage discountLink on plan
Pipedrive
Sales & CRM
14-day free trial; save up to 42% billed annually
Free periodDirect link
Salesforce
Sales & CRM
$3,000
CreditsLink on plan
Zendesk
Customer Support
6 months to 2 years free
Free periodApplication form
Intercom
Customer Support
$15,000
Percentage discountLink on plan
Mailchimp
Marketing & Growth
Free plan, 14-day Standard trial, 15% off for 12 months at 10,000+ contacts
Free planDirect link
Slack
Productivity & Collaboration
$9,000
CreditsLink on plan
Also mentioned on this page with nothing currently on offer: Xero. We track them so you do not have to go looking.
SaaS codes, all in one place
105 listings in SaaS, with the redemption codes and programme links behind one subscription. Browsing is free.
Common questions
What is the difference between a SaaS software stack and a tech stack?
The tech stack is what your product is built from: hosting, database, auth, billing. The software stack is what the company runs on: CRM, helpdesk, email, accounting, docs and banking.
When should a startup buy a CRM?
When two people need the same pipeline and you can no longer tell who last spoke to a prospect. Before that, a spreadsheet is faster to change and costs nothing to abandon.
Can one suite replace my whole company stack?
For a team under about twenty people, usually yes, and the saved integration work is worth the feature gap. It stops being true when one weak module blocks the team that depends on it daily.
How do I avoid vendor lock-in on business software?
Own your email domain, check export documentation before signing, and run a quarterly export from every system holding customer data into storage you control. Confirm the export actually opens.