How do you know if you have validated the problem space enough to start dedicating engineering resources to building out the product?

This is hard! For me, it's a mix of having a good understanding and confidence that you have 

(1) a clear hypothesis that you can test with a minimally viable product that is shaped by data and customer/market research,
(2) confidence that you have a potential solution that can prove the hypothesis correct, and
(3) an understanding of the risk and opportunity for building that solution, including the time it'll take to build, the availability of users willing to try your solution.

When in doubt, it's always a helpful rule of thumb (in my opinion) to simplify the scope of your solution as much as possible, to both reduce engineering time/complexity AND to not squander the opportunity cost of shipping too late (see the Reid Hoffman quote question posted as well!). The hardest one in my opinion is 1 - making sure that you get down to the real essence of an unmet customer need and being incredibly clear and specific on how you think your product can solve it, and how you will know.

Before investing in engineering resources you want to build conviction around the following:

1. Is there a market need? Are you fulfilling a true gap in the market?

2. Do you have a differentiated vision to deliver on this need?

3. Is there willingness to pay? 

4. Does the business model make sense such that you see a path to ROI for the business?

5. Is there a clear route to market (you know how to sell / acquire customers)?

6. Does your business have (or plan to have) the capabilities to deliver on this product (ex operational, technical or other expertise) such that it is strategic to expand in this direction?

Overall you want to be able to articulate what the investment unlocks for the company and how.

For a new product in a new market, I don’t think you can ever validate the problem space enough. Once you have reasonable confidence that the users (and buyers) exist for the problem space your product tackles, and there are viable ways to create a business out of that solution, the best next step is to involve engineering to build a prototype of the solution. Then you can test that prototype with a representative sample of the expected user base to get early feedback and iterate on building out the product and grow the business.

For 0-1 products, involving engineering early as a partner to the overall product definition and development process is best, so you can iterate together on building the right product for the right audience.

To ensure that you are investing your resources wisely, it is critical to have a high degree of confidence in the problem you are going after. You do not want to spend engineering resources on a problem that may not be large enough or is technically not possible to solve. Here are some key indicators that can signal you are ready to allocate engineering resources to building out the product. However, it's important to continue validating, testing, and iterating on the product as you move forward to ensure that it continues to meet the needs of your target audience.

• Market opportunity: You have conducted market research and have a clear understanding of the market opportunity for your product.

• Understanding of the customer problem: You have a clear understanding of the problem you are trying to solve, the target audience, and the key pain points that need to be addressed.

• Validation from potential customers: You have received validation from potential customers that the problem you are solving is important to them and that they are willing to pay for a solution.

• Clear product vision: You have a clear product vision that is aligned with the problem you are solving and the needs of your target audience. This includes a clear understanding of the features and functionality required to solve the problem.

• Defined product roadmap: You have a defined product roadmap that outlines the key features and milestones required to bring the product to market.

• Resources and budget: You have the necessary resources and budget to support the development and launch of the product.

• Competition: You have a clear understanding of the competitive landscape and have identified how your product will differentiate itself from the competition.

Validating the problem is of course a critical step in building a great product. A couple of signals to look for

• Do you have a clearly articulated problem statement you are trying to solve
• Did you conduct robust user research to narrow down your problem statement to know what you would be solving? Users' desire to buy and use a product to solve the problem is the best signal you are looking for to keep marching forward
• Business viability of the problem statement - This reflects the market you are playing in, and the business model you would consider. Have you estimated the cost of development and compared it to the potential return on investment? For B2B companies a great way to validate this is by getting Letters of Intents (LOIs). Its a nonbinding document saying the customer is willing to pay for it
• Lastly, I would say you should have a proof of concept in Figma or some prototyping tool and put it in front of customers. This step is critical because you will truly know what works or doesn't work. You can also start small with 1 engineer and slowly grow the team. 

Hence, before you put a ton of resources, try to take above actions. Once you have conviction, start small might teams who will build and iterate

Validating the problem space sufficiently before dedicating engineering resources is crucial. Indicators that suggest you are ready to proceed include: a clear understanding of customer needs, consistent feedback validating the problem, comprehensive market research and competitive analysis, alignment with business objectives, a potential market size and opportunity, confidence in achieving product-market fit, and risk mitigation through iterative learning.

By thoroughly researching the market, gathering feedback from potential users, and assessing the competitive landscape, you can understand the target customers, their pain points, and the viability of your product. Consistent validation from multiple sources strengthens the case for moving forward.

Additionally, aligning the problem space with your business objectives ensures strategic coherence. Evaluating market size, growth potential, and customer willingness to adopt your solution provides confidence in the market opportunity.

This is heavily dependent on the type of product you are building, but you can get very far with high fidelity designs and manually "hacking" things together. I worked at a company where we "generated" (hand created) an analytics report for a customer (who was actually paying us) once a month. It took an insane amount of time to create (20+ hours) but the feedback on both how to sell, and how to build our product from that experience were invaluable.

Start light: with high-fidelity designs and clickable prototypes. Once you have consistent signal from your ideal user persona saying that they would use the product if it existed, then get to work on a POC (proof of concept) only. Don't fully trust your customers just yet - you still need to prove that they will actually use it.

I believe all early initial engineering work should be treated as POC work. Piece together what you need to in order to get the validation that people will actually use it. At this point, you are building to learn, not to last.

Once you are starting to see usage and actual traction (and in parallel are having success in the market on positioning and selling), that's when the decisions around how to invest in engineering will come in. Again, this is highly dependent on the type of product you are building, but the biggest trap people fall into is focusing on scale before seeing any success.

Be scrappy at first, scale later. And build to learn.